Developing apparatus and developing method

ABSTRACT

A joint nozzle that delivers a developer, a rinsing liquid and nitrogen gas is disposed adjacent the spin center of a substrate in plan view. A controller operates electromagnetic switch valves to continue supply of the developer, while spinning the substrate, in a developing process, and to start supply of the rinsing liquid in a rinsing process, immediately after the supply of the developer ends, thereby achieving a shortened period of the developing process. A switching is made to a drying process by starting supply of the nitrogen gas immediately after completion of the rinsing process. Thus, even if the substrate has a large angle of contact, formation of droplets of the rinsing liquid is inhibited to prevent post-develop defects.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a divisional application of U.S. Ser. No.11/671,581 filed Feb. 6, 2007, which application claims benefit andpriority of Japanese application no. 2006-029963 field Feb. 7, 2006,which are incorporated herein in their entirety.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

This invention relates to a developing apparatus and development methodfor developing semiconductor wafers, glass substrates for photomasks,glass substrates for liquid crystal displays and flat panel displays,and substrates for optical disks (hereinafter called simply“substrates”).

(2) Description of the Related Art

As one of the methods of developing resist film formed on surfaces ofsubstrates, a puddle development mode is used widely (as disclosed inJapanese Unexamined Patent Publication No. 2003-109894, for example).This developing mode may be divided broadly into a developing process, arinsing process and a drying process as described below.

First, a developer is supplied while moving a developer nozzle relativeto a substrate, to form a puddle of the developer on the substrate. Inthis state, the substrate is maintained still for a predetermined periodto allow for progress of a development reaction (developing process).Subsequently, the substrate is spun while supplying a rinsing liquid(e.g. deionized water) to the substrate to stop the development reactionand clean the substrate (rinsing process). After the rinsing process,the supply of the rinsing liquid is stopped and the substrate is spun athigh speed to dry (drying process).

For this purpose, a developing unit has a spin-support device forrotatably supporting a substrate, the developer nozzle, and a rinsingliquid nozzle. A developing apparatus includes a plurality of suchdeveloping units to develop substrates in parallel.

(I)

However, a conventional apparatus having the above construction has thefollowing drawbacks.

The surface of a substrate to be developed has resist film formedthereon, and generally has a large angle of contact (which is an anglebetween the substrate surface and a tangent to each droplet), and thushas a strong tendency to repel liquid. As the wavelength of exposingmachines has become shorter from i-beam to KrF, and from KrF to ArF, theangle of contact of the substrate is becoming larger according to aresist material used. Moreover, considering the resist to be used inimmersion exposure expected to be implemented in the near future, theangle of contact is likely to become still larger.

When the angle of contact of the substrate becomes large, there arisesan inconvenience that the substrate cannot be dried effectively. Thisaspect will be described with reference to FIGS. 1A, 1B and 1C. FIGS.1A-1C are front views and plan views of a substrate in a rinsing processand a drying process in the prior art. FIG. 1A shows a state of arinsing liquid being supplied from a rinsing liquid nozzle 71 to a waferW in a spin. As seen, the rinsing liquid supplied onto the wafer W flowsfrom the center to edges of the wafer W to be discarded outward from thewafer W. At this time, a film R of the rinsing liquid is formed on thewafer W.

FIG. 1B shows a state of the supply of the rinsing liquid being stoppedand the wafer W being spin-dried. Most of the rinsing liquid forming thefilm R is discarded outward from the wafer W, but part thereof deformsinto droplets on the wafer W. In FIG. 1B, the droplets are shown withsign “r” affixed thereto. The larger angle of contact of the wafer W hasthe greater tendency to form the droplets “r” of the rinsing liquid.When the droplets “r” of the rinsing liquid are sufficiently small, thecentrifugal force produced by the spinning wafer W may fail to act onthe droplets “r” of the rinsing liquid, thereby allowing the droplets“r” to remain on the wafer W. The components of the resist will dissolvein the droplets “r” of the rinsing liquid remaining on the wafer W. Thisresults in an inconvenience that, as shown in FIG. 1C, the components ofthe resist dissolved in the droplets “r” of the rinsing liquid formdeposits, which become post-develop defects “k”, on the wafer W havingundergone a drying process.

(II)

The conventional method and apparatus have a drawback of requiring along time for developing substrates. Among the respective processes ofdevelopment, the developing process is the longest and takes up about ahalf of the total period of development. A development reaction whichprogresses in this developing process, specifically, is neutralizationat development interfaces. With progress of the neutralization, thealkali concentration of the developer deteriorates (lowers).Consequently, the neutralization at the development interfaces slowsdown gradually. This deceleration is taken into consideration indetermining a period for the developing process.

Since a long time is required for development, it is difficult toachieve a further improvement in the throughput of the developingapparatus. To increase the number of developing units in order toimprove the throughput of the developing apparatus is unrealistic fromthe viewpoint of cost and footprint

SUMMARY OF THE INVENTION

This invention has been made having regard to the state of the art notedabove, and its object is (I) to provide a developing apparatus and adeveloping method that can prevent generation of post-develop defectsdue to a large angle of contact of substrates, and (II) to provide adeveloping apparatus and a developing method for developing substratesin a reduced time.

The above object is fulfilled, according to this invention, by adeveloping apparatus for developing a substrate, comprising aspin-support device for rotatably supporting the substrate; a developernozzle for supplying a developer to the substrate; a rinsing liquidnozzle for supplying a rinsing liquid to the substrate; an inert gasnozzle for supplying an inert gas to the substrate; and a control devicefor controlling spinning of the substrate and supply of the developer,the rinsing liquid and the inert gas; wherein the rinsing liquid nozzleand the inert gas nozzle are juxtaposed in a position adjacent a spincenter of the substrate in plan view, and the control device startssupplying the inert gas to adjacent the spin center after supplying therinsing liquid to adjacent the spin center of the substrate being spun,and while a film of the rinsing liquid is present on the substrate.

According to this invention, the rinsing liquid nozzle and inert gasnozzle are juxtaposed in a position adjacent the spin center of thesubstrate in plan view. Thus, the inert gas can be supplied to adjacentthe spin center of the substrate, without displacing the rinsing liquidnozzle largely from adjacent the spin center of the substrate. Thecontroller can therefore switch instantly what is supplied to adjacentthe spin center of the substrate, from the rinsing liquid to the inertgas. Since the rinsing liquid and inert gas can be supplied to adjacentthe spin center of the substrate substantially from right above, therinsing liquid spreads over the substrate in concentric circles fromadjacent the spin center, and drying of the substrate progresses inconcentric circles from adjacent the spin center. In such construction,supply of the inert gas is started after supply of the rinsing liquid isstopped, and while the rinsing liquid remains in the form of film on thesubstrate surface. The inert gas supplied breaks the film of the rinsingliquid, and the substrate dries where the liquid film is broken. Theterm “adjacent the spin center of the substrate” is intended to meanalso the spin center of the substrate.

Since the substrate is spinning, once the film of the rinsing liquid isbroken, the broken portion will quickly enlarge toward edges of thesubstrate whereby the entire substrate will dry. In this way, thesubstrate changes from the state of having the film of the rinsingliquid formed thereon straight to the dried state. This allows no timefor formation of droplets of the rinsing liquid. Thus, even if thesubstrate has a large angle of contact, there is no possibility ofdroplets of the rinsing liquid remaining on the substrate. It is alsopossible to prevent post-develop defects due to the components of resistdissolving in the rinsing liquid.

The apparatus according to this invention may further comprise a drivingdevice for slightly moving the inert gas nozzle adjacent the spin centerof the substrate in plan view. With this driving device, supply of theinert gas can be started by slightly moving the inert gas nozzle in aprompt way.

The driving device may be arranged to move slightly also the rinsingliquid nozzle adjacent the spin center of the substrate in plan view.With the driving device constructed for slightly moving also the rinsingliquid nozzle, the rinsing liquid nozzle can be displaced as well as theinert gas nozzle being moved. With the driving device being shared bythe rinsing liquid nozzle and inert gas nozzle, the construction of thedeveloping apparatus is simplified.

In this invention, the developer nozzle may also be juxtaposed adjacentthe spin center of the substrate in plan view when the rinsing liquidnozzle is disposed adjacent the spin center of the substrate in planview; and the control device may be arranged, while spinning thesubstrate, to switch instantly from the supply of the developer toadjacent the spin center to the supply of the rinsing liquid to adjacentthe spin center. Since the developer nozzle and rinsing liquid nozzleare juxtaposed adjacent the spin center of the substrate in plan view,the rinsing liquid can be supplied to adjacent the spin center of thesubstrate without displacing the developer nozzle largely from adjacentthe spin center of the substrate. The control device can thereforeswitch instantly what is supplied to adjacent the spin center of thesubstrate, from the developer to the rinsing liquid. Thus, while a newdeveloper is continuously supplied to the substrate to prevent loweringthe rate of development reaction, the supply of the developer can bestopped at a desired time. Since the substrate is kept spinning, the newdeveloper spreads quickly over the entire substrate. The aboveconstruction can shorten the time required for developing the substrate,compared with the conventional puddle development mode.

In this invention, the rinsing liquid nozzle and the inert gas nozzlemay be integrated with each other. Then, it is possible to realizeconveniently the construction in which the rinsing liquid nozzle andinert gas nozzle are juxtaposed adjacent the spin center of thesubstrate in plan view, with each nozzle directed to the spin center ofthe substrate.

The developer nozzle may be integrated with the rinsing liquid nozzleand the inert gas nozzle. Then, it is possible to realize convenientlythe construction in which the developer nozzle and rinsing liquid nozzleare juxtaposed adjacent the spin center of the substrate in plan view,with each nozzle directed to the spin center of the substrate.

In another aspect of the invention, a developing apparatus fordeveloping a substrate, comprises a spin-support device for rotatablysupporting the substrate; a developer nozzle for supplying a developerto the substrate; a rinsing liquid nozzle for supplying a rinsing liquidto the substrate; an inert gas nozzle for supplying an inert gas to thesubstrate; and a control device for controlling spinning of thesubstrate and supply of the developer, the rinsing liquid and the inertgas; wherein the rinsing liquid nozzle and the inert gas nozzle arejuxtaposed as directed to adjacent a spin center of the substrate, andthe control device starts supplying the inert gas to adjacent the spincenter after supplying the rinsing liquid to adjacent the spin center ofthe substrate being spun, and while a film of the rinsing liquid ispresent on the substrate.

According to this invention, the rinsing liquid nozzle and inert gasnozzle are juxtaposed as directed to adjacent the spin center of thesubstrate. Thus, the inert gas can be supplied to adjacent the spincenter of the substrate, without displacing the rinsing liquid nozzlelargely from where the rinsing liquid nozzle has been supplying therinsing liquid. The controller can therefore switch instantly what issupplied to adjacent the spin center of the substrate, from the rinsingliquid to the inert gas. In such construction, supply of the inert gasis started after supply of the rinsing liquid is stopped, and while therinsing liquid remains in the form of film on the substrate surface. Theinert gas supplied breaks the film of the rinsing liquid, and thesubstrate dries where the liquid film is broken. The term “adjacent thespin center of the substrate” is intended to mean also the spin centerof the substrate.

Since the substrate is spinning, once the film of the rinsing liquid isbroken, the broken portion will quickly enlarge toward edges of thesubstrate whereby the entire substrate will dry. In this way, thesubstrate changes from the state of having the film of the rinsingliquid formed thereon straight to the dried state. This allows no timefor formation of droplets of the rinsing liquid. Thus, even if thesubstrate has a large angle of contact, there is no possibility ofdroplets of the rinsing liquid remaining on the substrate. It is alsopossible to prevent post-develop defects due to the components of resistdissolving in the rinsing liquid.

The developer nozzle may also be juxtaposed as directed to adjacent thespin center of the substrate when the rinsing liquid nozzle is disposedas directed to adjacent the spin center of the substrate, and thecontrol device may be arranged, while spinning the substrate, to switchinstantly from the supply of the developer to adjacent the spin centerto the supply of the rinsing liquid to adjacent the spin center. Sincethe developer nozzle and rinsing liquid nozzle are juxtaposed asdirected to adjacent the spin center of the substrate, the rinsingliquid can be supplied to adjacent the spin center of the substrate,without displacing the developer nozzle largely from where the developernozzle has been supplying the developer. The controller can thereforeswitch instantly what is supplied to adjacent the spin center of thesubstrate, from the developer to the rinsing liquid. Thus, while a newdeveloper is continuously supplied to the substrate to prevent loweringthe rate of development reaction, the supply of the developer can bestopped at a desired time. Since the substrate is kept spinning, the newdeveloper spreads quickly over the entire substrate. The aboveconstruction can shorten the time required for developing the substrate,compared with the conventional puddle development mode.

In a further aspect of the invention, a developing apparatus fordeveloping a substrate, comprises a spin-support device for rotatablysupporting the substrate; a developer nozzle for supplying a developerto the substrate; a rinsing liquid nozzle for supplying a rinsing liquidto the substrate; an inert gas nozzle for supplying an inert gas to thesubstrate; and a control device for controlling spinning of thesubstrate and supply of the developer, the rinsing liquid and the inertgas; wherein the developer nozzle and the rinsing liquid nozzle arejuxtaposed in a position adjacent a spin center of the substrate in planview, and the control device is arranged, while spinning the substrate,to switch instantly from the supply of the developer to adjacent thespin center to the supply of the rinsing liquid to adjacent the spincenter.

According to this invention, the developer nozzle and rinsing liquidnozzle are juxtaposed adjacent the spin center of the substrate. Thus,the rinsing liquid can be supplied to adjacent the spin center of thesubstrate, without displacing the developer largely from where thedeveloper nozzle has been supplying the developer liquid. The controllercan therefore switch instantly what is supplied to adjacent the spincenter of the substrate, from the developer to the rinsing liquid. Sincethe developer and rinsing liquid can be supplied to adjacent the spincenter of the substrate substantially from right above, the developer orrinsing liquid spreads over the substrate in concentric circles fromadjacent the spin center. Thus, while a new developer is continuouslysupplied to the substrate to prevent lowering the rate of developmentreaction, the supply of the developer can be stopped at a desired time.Since the substrate is kept spinning, the new developer spreads quicklyover the entire substrate. The above construction can shorten the timerequired for developing the substrate, compared with the conventionalpuddle development mode.

In a still further aspect of the invention, a developing method fordeveloping a substrate is provided, the method comprising the steps ofdeveloping the substrate by supplying a developer to the substrate;rinsing the substrate by spinning the substrate while supplying arinsing solution to the substrate; and drying the substrate by startingsupply of an inert gas to adjacent a spin center of the substrate afterfinishing the rinsing step and while a film of the rinsing liquid ispresent on the substrate.

According to this invention, supply of the inert gas is started aftersupply of the rinsing liquid is stopped, and while the rinsing liquidremains in the form of film on the substrate surface. The inert gassupplied breaks the film of the rinsing liquid. The substrate drieswhere the liquid film is broken. Since the substrate is spinning, oncethe film of the rinsing liquid is broken, the broken portion willquickly enlarge toward edges of the substrate whereby the entiresubstrate will dry. In this way, the substrate changes from the state ofhaving the film of the rinsing liquid formed thereon straight to thedried state, to be free from formation of droplets of the rinsingliquid. Thus, even if the substrate has a large angle of contact, thereis no possibility of droplets of the rinsing liquid remaining on thesubstrate. It is also possible to prevent post-develop defects due tothe components of resist dissolving in the rinsing liquid.

In the invention noted above, the developing step may continue supply ofthe developer until an end of a period allocated for the developingstep; and the rinsing step may start supply of the rinsing liquidimmediately after the supply of the developer ends. Since the developingstep continuously supplies the developer, a new developer is constantlysupplied to development interfaces to prevent lowering the rate ofdevelopment reaction. This can shorten the time required for thedeveloping step. The rinsing step starts supply of the rinsing liquidimmediately after the supply of the developer ends. Thus, the developingstep may be terminated instantly to prevent over-development, and togive way to the rinsing step. The above method can shorten the timerequired for developing the substrate.

The invention disclosed in this specification relates also to thefollowing developing apparatus and developing method:

(1) A developing apparatus for developing a substrate, comprising aspin-support device for rotatably supporting the substrate; a developernozzle for supplying a developer to the substrate; a rinsing liquidnozzle for supplying a rinsing liquid to the substrate; an inert gasnozzle for supplying an inert gas to the substrate; and a control devicefor controlling spinning of the substrate and supply of the developer,the rinsing liquid and the inert gas; wherein the rinsing liquid nozzleand the inert gas nozzle are juxtaposed in a position adjacent a spincenter of the substrate in plan view, and the control device isarranged, while spinning the substrate, to switch instantly from thesupply of the rinsing liquid to adjacent the spin center to the supplyof the inert gas to adjacent the spin center.

According to the invention set out in paragraph (1) above, the rinsingliquid nozzle and inert gas nozzle are juxtaposed adjacent the spincenter of the substrate in plan view. The control device can thereforeswitch instantly what is supplied to adjacent the spin center of thesubstrate, from the rinsing liquid to the inert gas. When the supply ofthe inert gas is started, the rinsing liquid remains in the form of filmon the substrate surface although the supply of the rinsing liquid hasstopped. Thus, the above apparatus has functions and effects similar tothe apparatus recited in claim 1.

(2) A developing method for developing a substrate, comprising the stepsof developing the substrate by supplying a developer to the substrate;rinsing the substrate by spinning the substrate while supplying arinsing solution to the substrate; and drying the substrate by startingsupply of an inert gas to adjacent a spin center of the substrateimmediately after finishing the rinsing step.

According to the invention set out in paragraph (2) above, the rinsingliquid remains in the form of film on the substrate surface immediatelyafter the rinsing step ends. In this state, the inert gas is supplied toadjacent the spin center of the substrate. Thus, the above method hasfunctions and effects similar to the method recited in claim 19.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the invention, there are shown in thedrawings several forms which are presently preferred, it beingunderstood, however, that the invention is not limited to the precisearrangement and instrumentalities shown.

FIGS. 1A-1C are front views and plan views of a substrate in a rinsingprocess and a drying process in the prior art;

FIG. 2 is a view showing an outline of a developing apparatus accordingto this invention;

FIG. 3A is a view in vertical section of a joint nozzle;

FIG. 3B is a view in cross section of the joint nozzle;

FIG. 4 is a timing chart showing a procedure of developing a substrate;

FIG. 5 is a schematic view showing a state of supplying a developer fromthe joint nozzle to the substrate;

FIG. 6 is a schematic view showing a relationship between line width ofa developed pattern and time as compared with a conventional puddledevelopment mode;

FIG. 7 is a schematic view showing a state of supplying deionized waterfrom the joint nozzle to the substrate;

FIG. 8 is a schematic view showing a state of starting supply ofnitrogen gas from the joint nozzle to the substrate;

FIG. 9 is a schematic view showing a state of starting supply ofnitrogen gas from the joint nozzle to the substrate;

FIG. 10 is a perspective view of a nozzle in a modified embodiment;

FIG. 11 is a perspective view of nozzles in another modified embodiment;

FIGS. 12A, 12B and 12C are plan views of a principal portion of amodified developing apparatus; and

FIG. 13 is a front view showing positions of modified nozzles.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of this invention will be described in detailhereinafter with reference to the drawings.

FIG. 2 is a view showing an outline of a developing apparatus accordingto this invention. FIG. 3A is a view in vertical section of a jointnozzle 11. FIG. 3B is a view in cross section of the joint nozzle 11.

The developing apparatus includes a spin chuck 1 for supporting, bysuction, the lower surface of a wafer W in horizontal posture. The spinchuck 1 has a vertical output shaft of a first motor 3 connected to thelower end thereof. The first motor 3 spins the wafer W at apredetermined rotational frequency. At this time, the wafer W has a spincenter C located on an extension of the output shaft of the first motor3. The spin chuck 1 and first motor 3 correspond to the spin-supportdevice in this invention.

The spin chuck 1 is surrounded by a cup (not shown) for collectingdeionized water, a developer and so on scattering from the wafer W. Thejoint nozzle 11 is disposed above the spin chuck 1 for deliveringnitrogen gas, a rinsing liquid and the developer.

Referring to FIGS. 3A and 3B, the joint nozzle 11 has a triple-tubestructure including a cylindrical outer tube 13, a cylindricalintermediate tube 15 inserted in the hollow of the outer tube 13, and acylindrical inner tube 17 inserted in the hollow of the intermediatetube 15. These outer tube 13, intermediate tube 15 and inner tube 17have a common central axis. The intermediate tube 15 and inner tube 17have lower ends extending to the same position in front view, while theouter tube 13 has a lower end thereof stopping short above the lowerends of the intermediate tube 15 and inner tube 17.

The intermediate tube 15 has, attached to a lower portion thereofprojecting downward from the lower end of the outer tube 13, a liquidbaffle 19 for mitigating a shock of the developer striking the wafer W.The liquid baffle 19 is shaped annular in plan view, and has an uppersurface 19 a thereof sloping down toward its outer peripheries. Theupper surface 19 a is curved to have a greater inclination toward theouter peripheries.

A space (hereinafter called “the first space”) A1, shaped annular inplan view, and defined between the inner peripheral surface of the outertube 13 and the outer peripheral surface of the intermediate tube 15,serves as a passage of the developer in the joint nozzle 11. One end ofdeveloper piping 21 is connected above the first space A1, and a lowerplane of the first space A1 serves as a discharge opening.

Similarly, a space (hereinafter called “the second space”) A2, shapedannular in plan view, and defined between the inner peripheral surfaceof the intermediate tube 15 and the outer peripheral surface of theinner tube 17, serves as a passage of the rinsing liquid in the jointnozzle 11. One end of rinsing liquid piping 27 is connected above thesecond space A2, and a lower plane of the second space A2 serves as adischarge opening.

The hollow (hereinafter called “the third space”) A3 of the inner tube17 serves as a passage of nitrogen gas in the joint nozzle 11. One endof nitrogen gas piping 35 is connected above the third space A3, and thelower plane of the third space A3 serves as a discharge opening.

When the joint nozzle 11 is located right over the spin center C of thewafer W, the above first space A1, second space A2 and third space A3are arranged in concentric circles adjacent the spin center C of thewafer W. In substance, a developer nozzle, a rinsing liquid nozzle and anitrogen gas nozzle are arranged one outside another, in plan view,adjacent the spin center C of the wafer W. It is therefore possible tosupply any one of the developer, rinsing liquid and nitrogen gasadjacent the spin center C of the wafer W. The joint nozzle 11corresponds to a construction integrating the developer nozzle, rinsingliquid nozzle and inert gas nozzle in this invention.

FIG. 2 refers again. A developer source 23 is connected to the other endof the developer piping 21. The developer source 23 is a containerstoring the developer, and is installed in this apparatus. Thesedeveloper piping 21 and developer source 23 function as a developersupplying device. The developer piping 21 has an electromagnetic switchvalve 25 mounted thereon.

Two branch pipes 29 a and 29 b are connected to the other end of therinsing liquid piping 27, which are connected to a deionized watersource 31 a and a surfactant solution source 31 b, respectively. Thedeionized water source 31 a may be provided as a utility in a cleanroom,for example. The surfactant solution source 31 b is a weighing tank formixing a surfactant and deionized water in a predetermined ratio. Inthis specification, deionized water and surfactant solution arecollectively called the “rinsing liquid.” These rinsing liquid piping27, branch pipes 29 a and 29 b, deionized water source 31 a andsurfactant solution source 31 b function as a rinsing liquid supplyingdevice. The branch pipes 29 a and 29 b have electromagnetic switchvalves 33 a and 33 b mounted thereon, respectively.

A nitrogen gas source 37 is connected to the other end of the nitrogengas piping 35. The nitrogen gas source 37 may be provided as a utilityin the cleanroom. These nitrogen gas piping 35 and nitrogen gas source37 function as a nitrogen gas supplying device. The nitrogen gas piping35 has an electromagnetism switch valve 39 mounted thereon.

An upper portion of the joint nozzle 11 is covered with a housing 41.The housing 41 contains a Peltier device 43 having both functions ofheat radiation and heat absorption for heating or cooling the outer tube13 of joint nozzle 11. This adjusts, en bloc, the temperatures of thedeveloper in the first space A1 and the rinsing liquid in the secondspace A2 of joint nozzle 11. The housing 41 and Peltier device 43correspond to the temperature control device in this invention.

One end of an arm 47 is connected to a lateral position of the jointnozzle 11, and the other end thereof is connected to a vertical rotaryshaft of a second motor 49. The joint nozzle 11 is driven by the secondmotor 49 to swing back and forth between a standby pod (not shown)disposed in a position offset from the wafer W and a position adjacentthe spin center C of the wafer W in plan view.

A controller 51 performs an overall control of the first motor 3, secondmotor 49, electromagnetic switch valves 25, 33 a, 33 b and 39, andPeltier device 43. The controller 51 is realized by a central processingunit (CPU) for performing various processes, a RAM (Random-AccessMemory) used as workspace of computations, and a storage medium such asa fixed disk for storing a variety of information. The controller 51corresponds to the control device in this invention.

Next, operation of the developing apparatus will be described withreference to the drawings. FIG. 4 is a timing chart showing a procedureof developing a substrate. Since developing treatment is divided broadlyinto a developing process, a rinsing process and a drying process asshown in FIG. 4, each process will be described separately hereinafter.It is assumed that amounts of heat radiation and heat absorption by thePeltier device 43 are controlled so that the developer and rinsingliquid in the joint nozzle 11 become a predetermined temperature.

<Developing Process: Time t1-Time t2>

When an exposed wafer W having photoresist film formed on the surfacethereof is transported into the developing apparatus, the wafer W issupported in horizontal posture on the spin chuck 1 by suction.Subsequently, the controller 51 starts the first motor 3 to spin thewafer W at a predetermined rotational frequency (several hundred rpm toseveral thousand rpm).

Then, the controller 51 operates the second motor 49 to swinghorizontally the joint nozzle 11 from the standby pot (not shown) toadjacent the spin center C of the wafer W, and keep the joint nozzle 11standing still there. While this swinging movement is conducted, thecontroller 51 opens the electromagnetic switch valve 25 having beenclosed, to direct the developer from the developer source 23 through thedeveloper piping 21 to the joint nozzle 11. The incoming developer flowsthrough the first space A1 in the joint nozzle 11, is adjusted to thepredetermined temperature, and delivered from the lower plane of thefirst space A1. The developer delivered collides with the upper surface19 a of the liquid baffle 19 over the entire circumference thereof, thenflows down the slope formed on the upper surface 19 a, and falls fromthe entire circumference of the edges of the liquid baffle 19.

The falling developer is first supplied to the edges of the wafer W inaccordance with the swing of the joint nozzle 11. After the joint nozzle11 has moved to adjacent the spin center C of the wafer W in plan viewand has stood still, and until time t2, the developer continues to besupplied to adjacent the spin center C of the wafer W.

FIG. 5 refers. FIG. 5 is a schematic view showing a state of supplyingthe developer from the joint nozzle 11 to the wafer W. As seen, when thedeveloper falling from the entire circumference of the edges of theliquid baffle 19 lands on the wafer W, the developer will, under acentrifugal force, flow and spread out over the wafer W. Part of thedeveloper will flow also inward from landing positions. The developer isscattered from the edges of the wafer W.

Thus, the wafer W constantly has a new supply of developer circulatingthereon. Since no deterioration occurs with the alkali concentration ofthe developer, the rate of development reaction (neutralization) ismaintained high throughout the developing process.

FIG. 6 is a schematic view showing a relationship between line width(CD: Critical Dimension) of a developed pattern and time, as comparedwith the conventional puddle development mode. In FIG. 6, the solid linerepresents this embodiment, and the dotted line the conventional puddledevelopment mode. Sign D in FIG. 6 indicates a desired value of linewidth. As seen, at development starting time t1, the line width of thedeveloped pattern has the same rate of decrease for this embodiment andthe conventional puddle development mode. That is, the rate ofdevelopment reaction is the same. However, while no time-dependentchange occurs in the rate of decrease of the line width of the developedpattern for this embodiment, the rate of decrease of the line width ofthe developed pattern falls with time for the conventional puddledevelopment mode. Thus, this embodiment, compared with the puddledevelopment mode, can decrease the line width of the developed patternto the desired value D in a short time.

<Rinsing Process (1): Time t2-Time t3>

At time t2, the controller 51 closes the switch valve 25 from the openstate, and opens the switch valve 33 a from the closed state. The firstmotor 3 is continuously operated to spin the wafer W at thepredetermined rotational frequency.

Consequently, the supply of the developer to the wafer W is stopped.Deionized water is directed from the deionized water source 31 a intothe joint nozzle 11. The deionized water flows through the second spaceA2, is adjusted to the predetermined temperature, and delivered from thelower plane of the second space A2.

FIG. 7 is a schematic view showing a state of supplying the deionizedwater from the joint nozzle 11 to the wafer W. The deionized waterdelivered falls straight to the wafer W and, under a centrifugal force,flows and spreads out over the wafer W. As a result, the deionized waterforms a film R on the wafer W. Part of the deionized water will flowalso inward from landing positions. The deionized water is scatteredfrom the edges of the wafer W.

By replacing the developer present on the wafer W with the deionizedwater as described above, the development reaction is stopped instantly.Consequently, as shown in FIG. 6, the development reaction can bestopped properly at a selected time when the line width of the developedpattern attains the desired value D.

<Rinsing Process (2): Time t3-Time t4>

At time t3, the switch valve 33 a in the open state is closed, and theswitch valve 33 b in the closed state is opened.

This effects a switching from the deionized water to the surfactantsolution. As is the deionized water, the surfactant solution isdelivered from the lower plane of the second space A2 after undergoingthe temperature control. The surfactant solution delivered flows overthe wafer W, whereby a film of surfactant solution is formed on thewafer W. For expediency, the same sign “R” as the film R of deionizedwater is affixed to the film of surfactant solution.

<Drying Process: Time t4-Time t5>

At time t4, the controller 51 operates the first motor 3 to spin thewafer W at an increased rotational frequency. The controller 51 alsocloses the switch valve 33 b from the open state, and opens the switchvalve 39 from the closed state.

Consequently, the supply to the wafer W of the surfactant solution isstopped. Nitrogen gas is directed from the nitrogen gas source 37 intothe joint nozzle 11, jetted down from the lower plane of the third spaceA3. The jetting of the nitrogen gas is started immediately after thesupply to the wafer W of the surfactant solution is stopped. Thus, thefilm R of the surfactant solution still remains over the entire surfaceof the wafer W.

FIG. 8 is a schematic view showing a state of starting supply of thenitrogen gas from the joint nozzle 11 to the wafer W. As seen, thenitrogen gas jetted blows away the surfactant solution, breaking itsfilm R adjacent the spin center C of the wafer W. The part adjacent thespin center C where the film R of the surfactant solution is brokendries.

Further, as shown in FIG. 9, once the film R of the surfactant solutionis broken, the broken part enlarges quickly outward over the wafer W,and the dried part also spreads quickly. In this way, the entire wafer Wis dried.

As drying progresses at a stretch, the wafer W changes from the state ofhaving the film R of rinsing liquid formed thereon straight to the driedstate. This allows no time for formation of droplets of the surfactantsolution. Even if droplets of the surfactant solution are formed, thedroplets can be scattered away from the wafer W by the centrifugal forceproduced by the spinning wafer W and the wind pressure of the nitrogengas.

The wafer W is dried until time t5 to complete the drying process.

As described above, the developing apparatus in this embodiment has thejoint nozzle 11 for delivering the developer, rinsing liquid andnitrogen gas. The different liquids and gas to be supplied to adjacentthe spin center C of the wafer W may be switched instantly only beopening and closing the electromagnetism switch valves 25, 33 a, 33 band 39 while the joint nozzle 11 is maintained still adjacent the spincenter C of the wafer W in plan view.

Specifically, deionized water can be supplied immediately after stoppingthe supply of the developer, thereby terminating the developmentreaction. This enables the developer to be supplied until just beforethe end of the developing process as in this embodiment. Consequently,the rate of the development reaction does not fall to the last. Sincethe period of the developing process can be shortened, the time taken toperform entire developing treatment can be shortened. Further, thedevelopment reaction can be stopped instantly by using a desired timingof switching from the developer to deionized water. It is thus possibleto perform proper development to obtain a developed pattern of desiredline width.

Since nitrogen gas is jetted immediately after stopping supply of thesurfactant solution, the wafer W can be dried quickly and directly fromthe state of having the film R of the surfactant solution on the waferW. This can inhibit formation of droplets of the surfactant solutioneven when the wafer W has a large angle of contact under the influenceof photoresist film, so that the surfactant solution tends to formdroplets. As a result, the surfactant solution does not remain on thewafer W long enough for the components of resist to melt into thesurfactant solution. There is no possibility of forming post-developdefects due to deposits of the components of resist present on the driedwafer W.

Even when droplets of the surfactant solution are formed on the wafer W,the droplets of the surfactant solution may be scattered away from thewafer W by the centrifugal force produced by the spinning wafer W andthe wind pressure of the nitrogen gas.

Since the joint nozzle 11 is located adjacent the spin center C of thewafer W in plan view, various gas and liquids can be deliveredsubstantially at right angles to the surface of wafer W. Consequently,the various liquids can be supplied to the wafer W so as to spread inconcentric circles from adjacent the spin center C of the wafer W. Thedrying of the wafer W by nitrogen gas may also progress in concentriccircles from adjacent the spin center C.

The joint nozzle 11 is swingable by the single arm 47 and single secondmotor 49, which simplifies the construction of the developing apparatus.

The surfactant solution supplied to the wafer W in the rinsing processhas a relatively weak surface tension. Thus, the surfactant solutionhaving entered the developed pattern is not scattered away or will neverpull the developed pattern when drying. This prevents falling of thedeveloped pattern, called a pattern collapse, occurring during thedrying process.

The temperature control of the rinsing liquid in the second space A2 ofthe joint nozzle 11 can suppress variations and extensions of the timerequired for the drying process. This inhibits post-develop defectscaused by dissolution of resist components.

The developer and rinsing liquid are subjected to the temperaturecontrol by the single, common temperature control device consisting ofthe housing 41 and Peltier device 43. This arrangement can simplify theconstruction compared with the case where separate temperature controldevices are provided.

The joint nozzle 11 having the liquid baffle 19 can cause the developerto reach the wafer W smoothly.

In time of starting the developing process, the developer is deliveredwhile the joint nozzle 11 is swung from the standby pot (not shown) toadjacent the spin center C of the wafer W in plan view. Thus, thedeveloper is first supplied to the edges of the wafer W. This inhibitsgeneration of micro bubbles involved into the developer landing on thewafer W, compared with the case of starting the supply of the developerat the center of the wafer W.

This invention is not limited to the foregoing embodiment, but may bemodified as follows:

(1) The foregoing embodiment includes the joint nozzle 11 for deliveringthe developer, rinsing liquid and nitrogen gas. The invention is notlimited to such construction.

As shown in FIG. 10, for example, a joint nozzle 61 may include a singlecylindrical body defining a single discharge opening in a lower positionthereof. As seen, the developer piping 21, rinsing liquid piping 27 andnitrogen gas piping 35 are connected to upper positions of the jointnozzle 61, and the respective liquids and gas are delivered from thecommon discharge opening.

As shown in FIG. 11, a developer nozzle 63 a, a rinsing liquid nozzle 63b and a nitrogen gas nozzle 63 c may be provided separately for therespective liquids and gas. In this case also, a single arm may beprovided for holding the developer nozzle 63 a, rinsing liquid nozzle 63b and nitrogen gas nozzle 63 c collectively. Alternatively, threeseparate arms may be provided for holding the developer nozzle 63 a,rinsing liquid nozzle 63 b and nitrogen gas nozzle 63 c individually.

The second motor 49 described in the foregoing embodiment may be appliedto the single arm or to the separate arms, but the followingmodification is possible. In the foregoing embodiment, the nozzle 11swung to adjacent the spin center C of the wafer W in plan view is madeto stand still there. The developer nozzle 63 a, rinsing liquid nozzle63 b and nitrogen gas nozzle 63 c swung to adjacent the spin center Cmay be further moved or rotated within a range adjacent the spin centerC of the wafer W in plan view. This further movement is a movement to aposition where the discharge opening of at least one of the nozzles 63a, 63 b and 63 c held adjacent the spin center C is directed to the spincenter C of the wafer W. The distance of this movement is about 20-30mm, for example. The further rotation is a displacement to direct thedischarge opening of at least one of the nozzles 63 a, 63 b and 63 cheld adjacent the spin center C to the spin center C of the wafer W. Themovement or rotation of the nozzles 63 a, 63 b and 63 c within a rangeadjacent the spin center C of the wafer W in plan view will be referredto hereinafter simply as “slight movement” to distinguish from theswinging movement in the foregoing embodiment.

The slight movement will be described with reference to FIGS. 12A-12C.FIGS. 12A-12C are plan views of a principal portion of a modifieddeveloping apparatus. A developer nozzle 64 a, a rinsing liquid nozzle64 b and a nitrogen gas nozzle 64 c are held together by a single arm 48to be close to one another and located on a swing track L. The dischargeopenings of the nozzles 64 a, 64 b and 64 c are directed straightdownward. The second motor 49 is connected to a proximal end of thesingle arm 48. The single arm 48 and second motor 49 correspond to thedriving device in this invention.

A controller not shown operates the second motor 49 to swing the nozzles64 a, 64 b and 64 c together from a standby position (shown in alternatelong and short dash lines in FIG. 12A) offset from a position over thewafer W to adjacent the spin center C of the wafer W, and at the sametime causes the developer to be delivered from the developer nozzle Ma.The swing of the single arm 48 is stopped when the developer nozzle Maarrives at a position over the spin center C of the wafer W (positionshown in solid lines in FIG. 12A). Consequently, the developer issupplied to the spin center C of the wafer W. When switching from thisdeveloping process to the rinsing process, the controller operates thesecond motor 49 to swing the single arm 48 slightly, whereby the rinsingliquid nozzle 64 b is moved to and maintained still in the position overthe spin center C of the wafer W (position shown in solid lines in FIG.12B). This slight swing corresponds to the slight movement noted above.Consequently, the rinsing liquid is supplied to the spin center C of thewafer W. When switching from the rinsing process to the drying process,the controller again operates the second motor 49 to move the single arm48 slightly, whereby the nitrogen gas nozzle 64 c is moved to andmaintained still in the position over the spin center C of the wafer W(position shown in solid lines in FIG. 12C). Consequently, nitrogen gasis supplied to the spin center C of the wafer W. Thus, also where theplurality of nozzles 64 a, 64 b and 64 c for supplying the differenttypes of liquid and gas, the developer, rinsing liquid and nitrogen gasmay be supplied to the spin center C of the wafer W by slightly movingthe nozzles adjacent the spin center C of the wafer W. The switchingbetween the different types of liquid and gas to be supplied can becarried out quickly through slight swinging movements. Thus, thismodification realizes a similar effect to the foregoing embodiment.Since the nozzles 64 a, 64 b and 64 c are moved slightly together, theapparatus has a simplified construction, and the control by thecontroller is never complicated.

The construction for slightly moving a plurality of nozzles is notlimited to the modified embodiment described with reference to FIG. 12.For example, the developer nozzle 63 a, rinsing liquid nozzle 63 b andnitrogen gas nozzle 63 c may be moved and/or rotated slightly togetherby a common actuator provided separately from the second motor 49. Thiscommon actuator may be disposed at the tip of the above single arm 48,or any other appropriate positions of the single arm 48.

The nozzles 63 a, 63 b and 63 c may be moved slightly and separatelyfrom one another by an actuator for the developer, an actuator for therinsing liquid and an actuator for the nitrogen gas. These actuator forthe developer, actuator for the rinsing liquid and actuator for thenitrogen gas may be arranged at the tip of a single drive mechanism, ormay be arranged in any appropriate positions of separate arms.

The nozzles 63 a, 63 b and 63 c may be moved slightly within a rangeadjacent the spin center C of the wafer W in plan view (e.g. within arange of about 20-30 mm) in accordance with actual timing of supplyingthe liquids and gas, so that the discharge openings of the nozzles 63 a,63 b and 63 c are opposed to the spin center C of the wafer W in order.

The single arm 49 or separate arms to which at least one of the commonactuator, the actuator for the developer, actuator for the rinsingliquid and actuator for the nitrogen gas is/are connected correspond(s)to the driving device in this invention.

The above driving device may be applied also to the joint nozzle 11described in the foregoing embodiment, to move the joint nozzle 11slightly adjacent the spin center C of the wafer W in accordance withtiming of supplying the liquids and gas, so that the liquid and gasdischarge openings of the joint nozzle 11 are opposed to the spin centerC of the wafer W.

(2) In the foregoing embodiment, the joint nozzle 11 is located adjacentthe spin center C of the wafer W in plan view, but the position of thenozzle is not limited to this. As shown in FIG. 13, a developer nozzle65 a, a rinsing liquid nozzle 65 b and a nitrogen gas nozzle 65 c may bearranged separately in positions displaced from adjacent the spin centerC of the wafer W in plan view. Each of the nozzles 65 a, 65 b and 65 chas a discharge opening directed to adjacent the spin center C of thewafer W. The liquids and gas are supplied from obliquely upwardpositions toward the spin center C of the wafer W.

(3) In the foregoing embodiment, the period for supplying nitrogen gasin the dry process may be changed as appropriate. That is, nitrogen gasmay be supplied from time t4 till time t5 when the drying process ends,or for only a short period from time t4.

(4) While nitrogen gas is supplied in the foregoing embodiment, anyinert gas, not limited to nitrogen gas, may be used.

(5) In the foregoing embodiment, the supply of the developer iscontinued in the developing process while spinning the wafer W. This isnot limitative. The developing process may employ the puddle developmentmode as in the prior art. That is, a developing process may be carriedout by forming a puddle of the developer on the wafer W, and thereaftermaintaining the wafer W with the puddle formed thereon still until thedeveloping process is completed. In this way also, it is possible toprevent generation of post-develop defects due to a large angle ofcontact of the wafer W.

(6) In the foregoing embodiment, deionized water is supplied to thewafer W in the first half of the rinsing process, and the surfactantsolution in the second half. This is not limitative. For example, thesurfactant solution may be supplied constantly throughout the rinsingprocess. Alternatively, deionized water and a surfactant may be suppliedin parallel, thereby forming a surfactant solution on the wafer W.

(7) The temperature control device in the foregoing embodiment is whatis called electronic cold heat having the housing 41 and Peltier device43. This may be replaced with a different known temperature controldevice as appropriate.

This invention may be embodied in other specific forms without departingfrom the spirit or essential attributes thereof and, accordingly,reference should be made to the appended claims, rather than to theforegoing specification, as indicating the scope of the invention.

What is claimed is:
 1. A developing method for developing a substrate,comprising the steps of: developing the substrate by supplying adeveloper to the substrate; rinsing the substrate by spinning thesubstrate while supplying a rinsing solution to the substrate; dryingthe substrate by spinning the substrate, including the step of startingsupply of an inert gas from a nozzle directed substantially at rightangles toward a point adjacent a spin center of the substrate in planview, after finishing the rinsing step and while a film of the rinsingliquid is present on the substrate; and wherein, when the rinsing stepends, the drying step is started; wherein, in said drying step, thesupplied inert gas breaks the film of the rinsing liquid, and saiddrying step continues supply of the inert gas until an end of a periodallocated for said drying step; said rinsing step replaces the developerwith the rinsing liquid; said developing step continues supply of thedeveloper until an end of a period allocated for said developing step;and said rinsing step starts supply of the rinsing liquid immediatelyafter the supply of the developer ends.
 2. A method as defined in claim1, wherein, when the developing step ends, the rinsing step is started.3. A method as defined in claim 1, wherein during the drying step, thenozzle stands still at said point adjacent the spin center of thesubstrate.
 4. A method as defined in claim 1, wherein said drying stepcontinues supplying the inert gas only until the supplied inert gasbreaks the film of the rinsing liquid.
 5. A developing method fordeveloping a substrate, comprising the steps of: developing thesubstrate by supplying a developer to the substrate; rinsing thesubstrate by spinning the substrate while supplying a rinsing solutionto the substrate; drying the substrate by spinning the substrate,including the step of starting supply of an inert gas from a nozzledirected substantially at right angles toward a point adjacent a spincenter of the substrate in plan view, after finishing the rinsing stepand while a film of the rinsing liquid is present on the substrate; andwherein, when the rinsing step ends, the drying step is started;wherein, in said drying step, the supplied inert gas breaks the film ofthe rinsing liquid, and said drying step continues supply of the inertgas until an end of a period allocated for said drying step.
 6. A methodas defined in claim 5, wherein, when the developing step ends, therinsing step is started.
 7. A method as defined in claim 5, whereinduring the drying step, the nozzle stands still at said point adjacentthe spin center of the substrate.
 8. A method as defined in claim 5,wherein said drying step continues supplying the inert gas only untilthe supplied inert gas breaks the film of the rinsing liquid.
 9. Adeveloping method for developing a substrate, comprising the steps of:developing the substrate by supplying a developer to the substrate;rinsing the substrate by spinning the substrate while supplying arinsing solution to the substrate; drying the substrate by spinning thesubstrate, including the step of starting supply of an inert gas from anozzle directed substantially at right angles toward a point adjacent aspin center of the substrate in plan view, after finishing the rinsingstep and while a film of the rinsing liquid is present on the substrate;and wherein, in said drying step, the supplied inert gas breaks the filmof the rinsing liquid, and said drying step continues supply of theinert gas until an end of a period allocated for said drying step; andwhen the supply of the rinsing liquid to the substrate is stopped, thesupply of the inert gas to the substrate is started.
 10. A method asdefined in claim 9, wherein, when the developing step ends, the rinsingstep is started.
 11. A method as defined in claim 9, wherein, when therinsing step ends, the drying step is started.
 12. A method as definedin claim 9, wherein during the drying step, the nozzle stands still atsaid point adjacent the spin center of the substrate.
 13. A method asdefined in claim 9, wherein said drying step continues supplying theinert gas until the supplied inert gas breaks the film of the rinsingliquid.